Ethical Experiments
by snakepit
Summary: Pure smut. [AU. LeviErenArmin. 3Way. Yaoi. Lemons.]


LeviErenArmin  
Attack on Titan ; Rated M ; Yaoi ; Lemons  
I don't own anything.

**Ethical Experiments**

/

It's been three weeks since Levi has been gone on his business trip. He should be home today so I thought I could pull off for a few more hours. I really thought that one last wank before he got here would be all that it would take to get my mind out of the gutter, but it wasn't enough. I couldn't stop thinking about what he'd do to me when he got home, what I'd do to him and the bruises we'd have in the mornings. The thought of his voice in my ears alone made me tremble.

So tonight; I supposed it was wrong to do what I was doing to Armin – but it's not like it had been the first time. Before Levi and still, after Levi, Armin had always been there to take care of my ache; my burning body and he caught all of my nimble movements as I caught his. I had done the same for him at one point in time and even Levi knew this. He had always made jokes about watching, saying we'd have to reenact it one day; never had I taken him seriously.

"Ar – min," I groaned his name as I lowered myself.

He was so different. Levi was thicker, but Armin was bigger – Levi's lips were chapped and tasted like ash, Armin's were soft and tasted like mint and chapstick – Levi's body was thin and boney; Armin's was soft and firm. The way he fucked me was even different. Levi would be pounding into me, pouring all of his rage into me and shoving my hips down and fucking me in every position, but Armin is gentle and slow. He's taking his time with meeting my thrusts. I couldn't complain though, I just couldn't _take_ it.

"Please," I was really begging. "Please, more!"

I arched my back and placed my hands behind me as an attempt to take him to the very hilt. It took everything in my power to keep myself up at this point and my knees felt like they could snap at any minute but I wasn't going to stop riding him now. If I let him get the upper hand then he'd just be gentle and I don't _want_ gentle.

With all that I could I fell onto him, burying him as deeply as I possibly could and shivering every time he entirely filled me. I took my shaft into my own hands considering Armin was, as per, being ever so gentle. So I took over, pumping myself quickly, bobbing my hips as hard as I could and rolling them every time I couldn't go any deeper. No matter how sensational it was; it still wasn't enough, it wasn't Levi.

As if right on cue, though, I could feel my heart stop when Armin's blue eyes widened from behind me. His soft little pants were replaced with silence before mine quickly halted. I slowly turned without even thinking of getting off of Armin. And sure enough, Levi stood there in the bedroom doorway; suitcase in hand and his outfit undone messily.

"L-Levi, I –" I was just as frozen as Armin.

"Kiss him," Levi interrupted any thought I had in my head when he let the suitcase fall to the wooden floor with a thud.

"W-what?" I asked.

"I said kiss him." He lazily pointed to our display before tugging his tie off and tossing it over the open closet door. I still didn't understand, but with all the fear inside of me I didn't hesitate to dip my head down and do as told. My stomach twisted before it heated even more and I hated myself that I was actually getting off to Levi watching us, watching _me_. Finally being here. I was so hypersensitive at the moment that I had gotten carried away. I pressed deeper, dipping my tongue between Armin's lips and relishing in the soft noises he made again, the gentle sound of our lips moving against one another.

"Don't stop," Levi's voice rang sharply in my ears and I could tell he was behind us. I could feel his hands on my hips pushing me forward into Armin's lips more until my end was high in the air and Armin was extracted from me. In a second I had pulled away to pout, and only to fall back down.

The familiar feeling of Levi's fingers twisted inside of me; still cold from the October air and rough – fuck, he was being so forceful. Levi's free hand dug into my spine; his nails clenching at my skin while Armin's softly trailed my neck and through my hair. I wanted to ask what Levi had planned doing but I knew I'd only get some snotty remark like '_what's it look like?_'. Instead I let myself be overcome by the warmth, I let my hands wonder down to Armin and I's shafts and cupped them together.

My lips went from Armin's, to down his jawline until I was sinking my teeth into the crook of his neck and the pained cry he released only encouraged me to bite harder. It's what Levi would like; and did like, I knew that when I could hear his zipper undo and feel him pierce me without warning.

"Lev… L –" My eyes rolled back with the sensation he brought. His thickness stretching me, tearing me and burying into me – I needed him. "_Deeper_." I exhaled the words against Armin's neck. I wasn't entirely sure Levi had heard me until I heard him groan. Underneath me Armin was wriggling, his hips were bucking into my hands and grinding against me before whimpers escaped his soft lips.

"Eren," Levi's arms wrapped around me before I was pulled backwards. My lips softly popped from being pulled from Armin's neck before they were separated again, this time with his fingers. Luckily he had at least remembered the decency to use his clean fingers, so I didn't take any time in allowing him entrance.

The hypersensitivity inside of me picked up every noise Levi had made, every sigh that passed his lips and every throb his cock made inside of me. All of my nerves came alive under his fingertips as he pressed his free hand to my stomach and wrapped his arm around my waist. My back fitted against his chest and he rested so deep inside of me; all I wanted was for him to hurry up and move.

"Armin," he removed his fingers from my mouth. "Turn over."

My blond friend hesitated at first, looking up at us with a flushed face and angelic eyes before that glimmer of blue turned into a lusty shadow and he did as told; rolling over onto his elbows with a few tremors wracking his spine. He was nervous and by the sounds of his trembling breath that was obvious.

"Ass up," Levi chimed before wrapping his hand around my aching erection. Oh god I wanted him to touch me; _more_, pound me and fuck me and this was driving me crazy. I tried to groan as a signal for that, but he only replied with a wry chuckle. What a fucking prick…

I had barely noticed once Armin had again complied, he looked back at us for a moment before Levi had taken the fingers that were covered in my saliva and lowered them to Armin's entrance. Armin was tight; that much was obvious by the way he tensed up when Levi slid a first finger into him. I wasn't even sure if Armin had ever been fucked before; other than the occasional girlfriend. But with another man? The cry he released by the time Levi had pushed a third finger in was telling me this was his first time.

It ended as quickly as it began; Levi removed his fingers and unwrapped his arm from my waist to take a hold of Armin's hips. He gave me a short thrust to make me scoot forward with him but all it did was make me whimper. I was frozen in place so he worked for me. He took my shaft into his own hands, and used his other to guide Armin's hips back. Somehow we had met in the middle and Levi successfully guided me to his entrance. By this point I leaned forward; I took my hands and put them over Levi's on Armin's small hips and forced myself into the restricting tightness.

"W-wait," Armin was white knuckling the sheets so I halted, trying to keep from hurting him. Levi on the other hand had other plans. He bucked his hips forward, driving my hips directly into Armin and burying me completely into the youngest. He cried out and tensed before looking back at me with tears in his eyes and pleas pouring from his bruised lips.

"Plea... please wait!"

"Why?" Levi asked over my shoulder before pulling out; doing so caused me to absent mindedly extract from Armin, only to be rammed back into and repeat the before effect. "You were fucking my fiancé." Levi cooed into my hair before digging his nails into my sides.

"I – no, wait!" Armin cried and I tried but Levi kept thrusting, hard and slow and making me pound into Armin even harder than he was pounding into me. "Eren – Lev – St… _ahh_!"

"Fine," Levi growled before shoving me down, completely on top of Armin. My chest pressed to his back and when I tried to pull upwards Levi only held his hands against my shoulders to keep me down. Trying to look back was pointless considering I was paralyzed in a silent scream. Levi's thrusts had gotten too hard too fast and while it hurt, I found myself wriggling between the two and pushing for all that I could get.

I reached for all that I could see; and that was Armin's fists. I laced our fingers together once he opened his hands and he only squeezed mine as hard as I did his; both white knuckling one another by this point. I was too deep inside of Armin to thrust downwards and Levi was pressing me down too hard for me to buck my hips. Burying my face into Armin's neck, I finally found some sound escaping my lips and pouring into the crook of Armin's neck.

"Don't - you want to - fuck him?" Levi leaned over now, still thrusting in just as deeply. I nodded frantically and heard the quiet panic in Armin's whimper. "Eren you're so deep inside him…" he cooed against the nape of my neck before placing a kiss there. "And I'm _so_ deep inside of you." With that, he bit down and earned the cry I knew he wanted. I was trapped between an enraged fiancé and a pained friend and right now all I selfishly wanted to do was touch myself.

"Please…" I whimpered out.

"Please – what?" Levi huffed between thrusts.

"Please... let me fuck Armin…"

One more senister chuckle from the dominated one before he quickly jerked me back up; his arms wrapped around my waist again. This time, however, I did pout and groan from my painful extraction. I knew Levi wouldn't care, though. He didn't even feel sorry when Armin cried out in nothing but pure pain.

"Turn back over Armin." Levi waited and watched him roll over. "Hold your legs up." His hands traced my inner thighs while we waited and his tongue prodded around the lobe of my ear. Armin had done as told and lifted his legs up before I guided myself to his puckered entrance. I was relieved when Armin's cries were cries of pleasure; and his arms wrapped around my neck. I complied in the kiss he wanted, lacing our tongues and burying my lips against his as Levi and I started a rhythm with our hips.

It was rough, hard and deep and I knew Armin couldn't stand it but he loved it. His eyes were half-lidded, tears were collected in his blue orbs and his face was such a rosy pink; all the more encouragement to impale him harder. His moans were so cute, squeaky and helpless and Levi's were so full of authority.

"I-I'm… going to –" I found Armin's lips again to hush myself. I didn't want to cum yet; but it didn't matter by the time I heard Levi's moans bubbling from behind me. Armin tightened around me and that's all it took to cause me to lose it. I spilled into him, the heat of my own essence pooling around myself and my entire body wracked with tremors.

"Wha…" Armin sat up a bit and Levi halted.

"Already?" I could see the grimace on Levi's face without even turning around.

"You came inside me!"

"You try being double penetrated!" I defended before rolling off. I winced a bit at Levi's sudden exit before I curled up and stared into Levi's slits for eyes. Armin was groaning a bit before it looked like he was going to roll off the bed but Levi pressed down.

"Then I'll fuck Armin." Levi smirked, looking more at Armin than me.

I didn't doubt him but it still took me for surprise when he scooted closer to Armin and fitted between his legs. I watched as my fiancé took no time in warning Armin of his penetration, rather than shoving himself in completely. Levi was thick; I knew that, but Armin didn't. Not until now when his back arched and his jaw dropped. I knew he was going to cry out again; in severe pain, so I captured his lips before he could do just what Levi wanted.

Selfishly, though, I wanted to watch…

Regretably, I pulled away from our kiss and instead trailed soft kisses around his cheek, under his eye and on his temple while his compressed windpipe whined.

"N-no, it hurts!" No matter how much Armin cried out I knew Levi would have no mercy, and certainly he wasn't going to stop. He had already started thrusting – hard enough to leave the sound of slapping skin echoing in the small room. Harder than I think he's ever fucked me. A bit of me was jealous at that but I returned my attention back to Armin, tracing my tongue against his earlobe and chuckling when he whimpered.

"Two times - in a row," Levi smirked and looked down at the blond before lowering himself. He nuzzled his face into the opposite side of Armin's neck. "I'm going - to cum - inside." I could barely hear him mumble the words into Armin's ear before he raised his head.

Our eyes met while Armin cried out, begging Levi not to but as I said before. No mercy.

I didn't even try to stop him or involve myself any more than meeting Levi in the middle and claiming his lips for my own. The taste of Levi; the after-taste of cigarettes still lingered on his tongue and I wanted so much more already.

"I – I'm c-cum… cumming!" Armin's eyes were squeezed tight when I pulled away from Levi who only smirked. He kept his pace up, getting quicker over the next few seconds before his fingers dug into the sheets and I knew he was cumming. I knew by the look on his face; the way he tried to hold down his moans and keep his mouth closed, so it came out as an exhale of heavy air before his eyes squeezed shut. I even knew how Armin came; his head would fall back and his eyes would barely stay open. Right on cue, again, Armin did just that while his own essence sprayed over himself, onto his and Levi's chest.

"Nnh…" Armin looked from Levi to me and his face was purely red now. I bit my lip a bit as I watched Levi pull away and out; both of our seed pouring out of Armin and onto the sheets. I smiled to Levi who wryly smiled back.

"What a fucking mess," he sarcastically rose his voice before standing and replacing his pants. "I need a shower. Is anyone going to join me?"Armin turned over and hugged himself before burying his face into the pillows. His silence said it all and Levi seemed only to be proud of the pain that he was in.

"Eren, you coming?"

I nodded before crawling over Armin. It had been fun and all, but now I needed Levi to myself.

* * *

**Sequel; Routine**


End file.
